We present several theorems on strict and strong convexity, and higher order differential formulae for sandwiched quasi-relative entropy (a parametrized version of the classical fidelity). These are crucial for establ...
详细信息
We present several theorems on strict and strong convexity, and higher order differential formulae for sandwiched quasi-relative entropy (a parametrized version of the classical fidelity). These are crucial for establishing global linear convergence of the gradient projection algorithm for optimization problems for these functions. The case of the classical fidelity is of special interest for the multimarginal optimal transport problem (the n-coupling problem) for Gaussian measures.
Reducing the information transmission delay in the Vehicular Ad Hoc Networks(VANETs) can improve the timeliness of receiving information and avoid the happening of the accident. As a potential solution, cooperative tr...
详细信息
Reducing the information transmission delay in the Vehicular Ad Hoc Networks(VANETs) can improve the timeliness of receiving information and avoid the happening of the accident. As a potential solution, cooperative transmission,which may effectively reduce the transmission delay by exploiting spatial diversity, has attracted lots of attentions recently. In this paper, we modeled the information transmission delay minimization of the VANETs in which cooperative transmission is allowed, and proposed a gradient projection algorithm based on the model. The RSU can schedule the vehicle transmission behavior according tothe algorithm, soas tosolve the problem of the information transmission delay minimization in the VANETs where multipath routings(MRTDM) are ***, our simulation results show that the algorithm not only has good convergence, but alsocan solve the MRTDM in VANETs.
Unmanned aerial vehicles (UAVs) can be used as aerial wireless base stations when cellular networks go down. Prior studies on UAV-based wireless coverage typically consider downlink scenarios from an aerial base stati...
详细信息
Unmanned aerial vehicles (UAVs) can be used as aerial wireless base stations when cellular networks go down. Prior studies on UAV-based wireless coverage typically consider downlink scenarios from an aerial base station to ground users. In this paper, we consider an uplink scenario under disaster situations (such as earthquakes or floods), when cellular networks are down. We formulate the problem of optimal UAV placement, where the objective is to determine the placement of a single UAV such that the sum of time durations of uplink transmissions is maximized. We prove that the constraint sets of problem can be represented by the intersection of half spheres and the region formed by this intersection is a convex set in terms of two variables. This proof enables us to transform our problem to an optimization problem with two variables. We also prove that the objective function of the transformed problem is a concave function under a restriction on the minimum altitude of the UAV and propose a gradientprojection-based algorithm to find the optimal location of the UAV. We validate the analysis by simulations and demonstrate the effectiveness of the proposed algorithm under different cases.
暂无评论